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My engine runs but, no drive??

A

Alkd

New member
I was @ cruzing speed when a pontoon cut in front of me, So Ill admit I paniced and yanked the throttle into reverse and now the drive unit doesnt move but the engine still runs I dont feel its the drive shaft becouse I dont hear it slapping around when I engauge it to gear Any ideas??
 
I'm betting, if it's an AQ drive, you snapped the verticle drive shaft either just below the top coupler or just above the the lower pinion gear.
 
I'll put my money on what Gary suggested.

Mean while:
Remove the shift mech, peek inside, spin the prop shaft and see if the sliding sleeve is rotating. The gears will not rotate, but the sliding sleeve should.

If you don't want to remove the shift mech, lock the drive in FWD, and try to spin the prop against normal direction.
If you can spin it, then you have an issue with the lower unit not rotating the vertical shaft..... either the lower shaft, or the spline coupler let go, and the lower shaft is not rotating the transmission's vertical shaft.

There is nothing in the transmission that would let go without some major damage...... and you would certainly hear this when the engine is running.

If single prop lower, you have two gears there...... a "drive" gear and a "driven" gear!
The lower unit drive gear may have cracked!
The drive gear/vert shaft splines may have stripped!
Or the vertical shaft coupler may have snapped (some have a cut in them to create a break point).

.
 
O.k. guys thanks I was looking through the service manual and I think Ill do as you say Ricardo, first Im going to start with the shift mech. it looks easy enought to pull off Oh by the way Its a volvo 740 w/ Dp D1 , and when its in gear the props spin free and I dont hear any noise in the drve could I be so lucky to have a shear pin that my have snapped? Ill let yins know what happens!
 
Alkd said:
O.k. guys thanks I was looking through the service manual and I think Ill do as you say Ricardo, first Im going to start with the shift mech. it looks easy enought to pull off.
Oh by the way Its a volvo 740 w/ Dp D1 , and when its in gear the props spin free and I dont hear any noise in the drve could I be so lucky to have a shear pin that my have snapped? Ill let yins know what happens!
Click to expand...
BTW, the props will spin in the direction of normal rotation while in gear. This causes no torque to the sliding sleeve/gear cup.
To test, you must go "against" this direction to see if you can get the sliding sleeve to grab into the gear cup!
However, from what you describe, this is not an option.

There is no shere pin to speak of. The drive may use the vertical shaft spline coupler that has the little groove machined into it. The intent is for this coupler to shere at this location, rather than greater damage elsewhere.

Good news.... these are very easy drives to work on!
(see my previous post, and run down that list of things to check)

Fingers are crossed for you.
 
Thanks again Rickardo, I stopped at my local volvo dealer and he had mentiond the same coupler as you said thats going to be todays project I hope!!
 
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